1. Field of the Invention
The present invention is directed to an apparatus in combination with a north seeking gyro to determine the azimuth position of a remote object for positioning of the remote object relative to the azimuth. More particularly, the present invention is directed to a rotating transfer arm mounted on a north seeking gyro that permits the north seeking gyro to be maintained stationary as the transfer arm is aligned with the remote object to determine its relative position.
2. Description of the Prior Art
Various attempts have been made in the prior art for determining the position of a remote object with respect to the azimuth in a relatively short period of time. For example, in directional equipment that is mounted on mobile trucks where it is desired to align the equipment relative to the true north, it has often been necessary to expend a considerable amount of time surveying the proposed location and establishing the exact alignment of true north at the site. After the direction of true north has been established and marked at the site by, for example, positioning blocks, it was necessary to utilize a number of theodolites as angle measuring devices for transferring the azimuth from the calibrated blocks to the remote object. Since the truck carrying the equipment can have a variable location relative to the mounting blocks, it was necessary to provide a theodolite with a parallel slide for moving the established angular relationship between the theodolite and another theodolite mounted above one of the mounting blocks to a perpendicularly aligned prism mounted on the guidance platform of the equipment. The time and effort involved was extensive and meant that the equipment remained inoperative for an excessive period of time before it could be properly aligned. Further, it was necessary to employ a surveying team to establish the position of the mounting blocks at the site location before the equipment could become operative. Generally, it has been found that depending on the latitude, the true north can be approximated within a plus or minus seven degrees for aligning equipment. However, the exact alignment to the azimuth within a range of seconds has been found to be extremely difficult.
Frequently, celestial sightings have been utilized to determine the true north. This method, however, suffers the disadvantage of being subjected to environmental weather conditions.
Recently, a rugged north seeking gyro has been developed, as disclosed in the Ambrosini U.S. Pat. No. 3,512,264 granted May 19, 1970 which permits an exact determination of the true north within a remarkably short period of time. However, as can be appreciated by those skilled in the art, a north seeking gyro instrument pendulously or otherwise mounted in extremely sensitive to any movement once it has been activated and nears final alignment.